Program Trading Accounts
For 53.2% of NYSE Volume

a Wall Street Journal Staff Reporter

Updated Aug. 27, 2004 12:01 a.m. ET

NEW YORK -- Program trading in the week ended Aug. 20 accounted for 53.2%, or an average of 678.6 million shares daily, of New York Stock Exchange volume. Brokerage firms executed an additional 445.6 million daily shares of program trading away from the NYSE, with 2.7% of the overall total on foreign markets. Program trading is the simultaneous purchase or sale of at least 15 different stocks with a total value of $1 million or more.

Of the program total on the NYSE, 10.9% involved stock-index arbitrage. In this strategy,...